Method of fabricating a one-piece metal vehicle wheel by hydro forming process

Abstract

A new method of building a vehicle wheel utilizing “hydro forming” from a solid piece of steel metal sheet.

The invention claimed is: 
     
       1. A method of fabricating a single-piece vehicle wheel including a rim and a hub, comprising the steps of:
 a) providing a strip of a steel sheet metal; 
 b) forming said steel sheet metal strip into a cylinder; having an open end and a closed end, having a height of at least 1.3 to 1.8 times longer than a finished height of said wheel; 
 c) trimming said open end of said cylinder to a desired dimension; 
 d) placing said trimmed cylinder on a special hydraulic press machine; 
 e) hydro-forming said trimmed cylinder into a desired shape; wherein said machine comprises an upper mold rod and a bottom mold matrix for forming a hub; wherein said upper mold rod comprises an embedded fluid path vertically passing through a center length of said upper mold rod, where fluid enters inside said trimmed cylinder; wherein said press machine further comprising multiple ejector pins located on a bottom jack of said press machine and around said bottom mold matrix; and a holder plate that is fixedly attached to said multiple ejector pins; two hydraulic jacks extending out from said holder plate, each having a jaw facing towards said trimmed cylinder and holding said trimmed cylinder fixedly in place during said hydro-forming step; wherein each of said jaws having a height equal to or longer than said trimmed cylinder height, therefore completely encompassing said trimmed cylinder inside; said press machine further comprises a pressure valve for opening and closing said fluid path for entrance of pressurized fluid of a fluid reservoir inside said trimmed cylinder during said hydro-forming step and guiding excess fluid out of said wheel when said hydro-forming step is completed; and wherein a design and shape of said upper mold rod, said bottom mold matrix and each of said jaws creating said desired shape after said trimmed cylinder is hydro-formed; 
 f) adjusting a height of said bottom jack and therefore said holder plate to an extent where each of said jaws are placed along said trimmed edges of said cylinder, therefore sealing said trimmed edge with said upper mold rod and therefore preventing an outflow of said fluid during said hydro-forming step; 
 g) closing each of said jaws via said two hydraulic jacks; 
 h) harnessing said trimmed cylinder in place and simultaneously injecting said fluid inside said trimmed cylinder via said fluid path wherein said trimmed cylinder is completely surrounded with said fluid; and moving down said upper mold rod and shutting off said fluid via said pressure valve; 
 i) adjusting pressure of said fluid and a pressure applied by said upper mold rod and each of said jaws so that said fluid forces said trimmed cylinder to fold and form via a uniform compression towards empty spaces of each of said jaws and said bottom mold matrix; 
 j) removing said fluid and commanding said upper mold rod and said bottom matrix of said press machine to return to their original positions; and 
 k) opening each of said jaws and releasing said wheel, wherein steps (a) through (k) are performed in the recited order. 
 
     
     
       2. The method of  claim 1 , wherein said pressure valve is a one-way mechanical or electrical valve. 
     
     
       3. The method of  claim 2 , further comprising the steps of:
 l) punching a valve hole, air holes, a central hole and plurality of bolt holes on said wheel; 
 m) rounding an edge of each of said valve hole, said air holes, said central hole and said plurality of bolt holes; and 
 n) coating and painting visible outer edges of said wheel. 
 
     
     
       4. The method of  claim 3 , further comprises the following steps:
 o) adjusting a height of said bottom jack, therefore placing each of said jaws of said holder plate along said trimmed edges of said trimmed cylinder; 
 p) closing each of said jaws by said hydraulic jacks at the starting up/turning on of said press machine; and at the same time injecting said fluid inside said trimmed cylinder via said one-way pressure valve.